Vacuum tube socket



Oct. 25, 1932. A l, CAWFORD 1?884,582

VACUUM TUBE S OCKET Filed Sept. 2l. 1928 /N VEN 70H A. l CRAM-ono ALLEN l.. CBAWEORD, 0F NEW YGRK, N. Ya SSIGN'OR T0 BELL TELEHQNE LABOBI- TGBES, ENCORURATED, OF NEW YORK, N. Y., A CORPGRATON 0F NEW YORK 'VACUUM TUBE SOCKET Application tiled September 21? 1928. Serial No. 307,35.

rlliis invention relates to sockets forvacnum tubes, and in particular to sockets tor vacuum tubes in which a plurality oi electrodes extend from the base of the tube,

Heretoore sockets for the push type vacuum tubes consisted of a disc or block of insulating material having apertures Jtherein to receive the electrodes of a vacuumv tube base, these electrodes engaging leaf springs Within the socket located in alignment Witb. the apertures. The disadvantages of this construction are the 'diliculty of maintaining the proper resiliency in the leaf springs after the tube has been put in and taken out a num ber of times9 and the small amount oi' contact area presented by thecontact springs to the electrodes of the tube.

Another t jpe oi socket for push type tubes consists of four lielical springs mounteo in spaced relation in a block or" insulating maa slightly greater diameter than the bottom, lt has been found that iter a tube has been i ut in and taken out o this type of socket a few times, the spring takes a set, thereby releasing the tension of the spring on the electrodes and consequently making very poor contact. This renders the socket practically useless.'

rlie object of the present invention is to provide a socket fthe latter type which is eticient in use an oieap to manufacture.

in accordance with this invention then novided two discs or insulating in; paced apart trom each other uv means or" studs, one disc being the face ot the socket and the other being tlie base. ne `disc 'orming the 'face of tbe socket is provided with e pertures arranged to accommodate the terterial, the upper end i each spring being of f min-al pins or" a vacuum tube havingT a push type base. Mounted in alignment with these apertures and extending in a downward direction to the base plate ofthe socket are t'our sets oi double Wound internieshed helical springs. Each set of springs consists of one right-hand Wound spring 'and one left-hand Wound spring. These springs are forced together to provide intermeshed helices having substantially an elliptical cross-section.

This arrangement provides a compact apertures 13 are of a smaller diameter.

socket for vacuum tubes having bases of tbe push type, in which ti-e electrodes on the base ot the tube, having a substantially circular cross-sectional area are forced into intimate contact with the intermeehed springs due to 5 the elliptical cross-section of the springs. A feature of the invention is the intermesh ing of a right-liand wound helical spring and u. left-hand Wound helical spring which when the prongs of a vacuum tube are `inserted therein exert pressure and make contact with a large area of the prong'.

Other features ot the invention Will be apparent from the following detailed de cription in connection with the accompanye ing drawing, in which Fig. l is a cross-sec'- tional view'7 taken at 1-1 on Fig. 2, of a vacuum tube socket made in accordance with the 'present invention with a vacuum tube in serted therein; llig. 2 is a plan View of the socket shown in l with a portion broken away to illustrate the position of one of the contact members; Fig. 3 is an enlarged vier-v of one of the contacts with the turns of each helixA intermeshed; ig. Ll illustrates the contact member before the helices bave been in termeslied.

Referring now to Fig. L, the .socket ot the invention comprises three discs-oi insulating material, su'ch as hard rubber or thc like, tbe base portion ot the socket consisting of the disc 5 and the top portion of the socket consisting of the two discs t? and 7, the disc being made of much thinner material than 'iii 1 `i; ,w f- L1 f I n Q.. tue also l, rorms me rice or ne socket. @ees cured to the base et the cir il are the studs il, with. il at nien secured to the discs *f5 and '7 bj; mf screws l0, ther-cbj,r holding in deinire spia; relation the disc 5 which forms the base and the discs 6 and 7 which torn; the top portion of the socket.

Located in the base are recesses l'i, usually l in number, which are arranged at tour corners of a square around the axis of the 9U' base 5. iThe discs 6 and 7 are pro rided with apertures 12 and 13, the apertures l2 being the saine diameter as the recesses l1, While the The apertures'lQ and lin the discs and 7 are in le@ upper ein -by providing a central oricewhich has a substantially elliptical cross-section as shown at 17 of Fig. 2. Thus whenV the customary i circular terminal pinsl9 of the vacuum tube 18 arelpushed into the elliptical orifice the turns of the helices 15 and 16 make contact along the entire length of the terminal pins 19. This is clearly shown in Fig. 1 wherein the vacuum tube 18 having the customary terminal pins 19 in thebase 20, has been inserted into the socket. 'i

and a. plurality of sets of springs each set comprising double Wound intermeshed helical springs, one end of each set resting 1n an aperture and the otherfend in a recess in alignment therewith, said springs having soldering .terminals integral therewith and bent at rlght angles tothe axes of their respective sprlngs. In witness whereof, I hereunto subscribe my name this 20th day of September, 1928. ALLEN l. CRAlVFORDY.

i The contact members'fll due to theirlnovel Y construction are provided with the terminal lugs 21 which are integral with the contact member. These terminal lugsV are located the grooves 22 of the disc 7 and are held in place by means of the disc 6 which is fastened thereon. f l

While the intermeshed helical contacts have been disclosed as being mounted between two discs of insulating material, it is apparent that other constructions would readily adapt themselves YYto this type of contact, for example, a melded block of insulating material having the 'contactsprings mounted therein. Furthermore the inventionis not limited to a vacuum tube socket since other receptacles lmay be madegwith the novel intermeshed helical contact arrangement without departing from the, spirit of the invention as defined in the anpendednclaims.YY Y.

What is claimed is:

1. A socket for electrical devices comprising a top portion having a number of aper; tures therein and a recess concentric with each of said apertures, a base portion provided with an Vequal number oi circular recesses, means for placing each of said apertures Hin alignment with va corresponding one of the last mentioned recesses, and contact members between said top and said base portions, said members comprising springs formed as helices, one pair for each aperture, said helices being substantiallyr concentric with sald apertures and seated at both ends in said recessed portions.

2. Asocket for an electrical device comprising an insulating member having a plurality of recesses therein, a second insulating memr having aA plurality of apertures therein, means for holding said insulating members in spaced relationship, the apertures and Yrecesses of said members being in alignment, 

